1. Field of the Invention
This invention relates to switching devices and more particularly to a step-on foot switch.
2. Prior Art
Step-on foot switches are known to the art of industrial technology and are used for numerous purposes such as, for example, automatic door opening devices of the type used at department stores and machine dis-able devices used to turn off machines when entering hazardous areas. Such prior art step-on foot switches have generally been inset into relieved areas of the flooring.
On motor adjustable X-ray equipment, particularly tilt bed patient X-ray devices, there are danger areas in which an operator's foot can become trapped between the floor and moving portions of the machinery. German Auslegeschrift 2,149,240 proposes to protect those areas through the usage of step-on foot switch devices placed on the floor adjacent such areas. Further German Offenlegungsschrift 2,148,760 teaches a foot switch applicable for such uses. This later publication discloses a foot switch which is to be placed on the floor and which is constructed in such a way that electrical contacts positioned between a floor or base plate and a foot plate, held in suspension above the floor plate by springs, are opened when the foot plate is stepped on. However the contact switches used in this prior step-on switch require a considerable minimum constructional height. Although this height is less than if standard commercial switches were used, it nevertheless is sufficiently high as to create the possibility of operator stumbling. Further, in such prior art foot switches for X-ray safety controls, a distinct disadvantage arose from the fact that small objects such as bolts, nuts, screws, dirt, which had fallen to the floor could get under the overlying foot plate thereby preventing proper operation.
It would therefore be an advance in the art to provide a step-on foot switch for such X-ray diagnostic equipment which could be placed on a level floor and which is as flat as possible so as to reduce or eliminate any likelihood that operating personnel will stumble on the switch and to further provide such a switch which is protected from intrusion by objects on the floor.